Vulnerability in Markdown-It Linkify-It
CVE-2026-59887
linkify-it is a links recognition library with full Unicode support. Prior to 5.0.2, the mailto: schema validator used by .test() and .match() can be invoked at every mailto: occurrence and scan the remaining input through src_email_name in lib/re.mjs, causing O(n^2) CPU consumption on crafted user text. This issue is fixed in version 5.0.2.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.006 (49.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 49.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.006 · change: +0.002
Affected products
- Markdown-It Linkify-It — versions < 5.0.2
Weakness classification (CWE)
References
- github.com/markdown-it/linkify-it/security/advisories/GHSA-v245-v573-v5vm (Exploit, Mitigation, Vendor Advisory)
- github.com/markdown-it/linkify-it/commit/105e5d77f7d119871d2b2d86ed208568eb3e7f… (Patch)
- github.com/markdown-it/linkify-it/releases/tag/5.0.2 (Release Notes)
Frequently asked questions
- What is CVE-2026-59887?
- CVE-2026-59887 is a high-severity vulnerability in Markdown-It Linkify-It, classified under Inefficient Algorithmic Complexity. CVSS score: 7.5/10. Published 2026-07-08.
- How severe is CVE-2026-59887?
- High severity. CVSS v3 base score is 7.5 out of 10.